Doximity doubles space

Doximity, which gives doctors an online site for networking, has doubled its San Mateo headquarters from 2,400 square feet to 4,900 square feet, officials said.

The office, at 60 E. 3rd St., includes suites 115 and 120.

Doximity’s headcount is now 57, up from 39 at the beginning of last year. The three-year-old startup, led by CEO Jeff Tangney, says 250,000 physicians — about one in three nationally — use its free service.

Earlier in his career, Tangney was co-founder of Epocrates Inc., also based in San Mateo. That company was bought by Athenahealth in 2013 for $293 million.